This invention relates to a rotating electrical machine (a motor or a generator, or a motor/generator) which has a cooling mechanism.
Tokkai Hei 4-364343 published by the Japanese Patent Office in 1992 discloses a rotating electrical machine which uses an inner section of a slot of a stator as a cooling passage. In this rotating electrical machine, components which generate heat such as the stator coils or the stator can be directly cooled by coming into direct contact with a cooling medium, for example a cooling oil, which flows in the slot. When forming the cooling passage, a mold is disposed in the inner section of the slot and on the inner periphery of the stator. A resinous material is injected in order to fill the space defined by the stator core and the mold. The resinous material hardens and covers the slot opening.
Since the conventional example of a rotating electrical machine displays poor sealing characteristics between the stator core and the resinous material, the cooling medium may leak from the juncture of the stator core with the resinous material. Leakage of cooling medium from the inner peripheral surface of the stator towards the rotor increases friction during rotation of the rotor and therefore adversely affects the rotating efficiency of the rotating electric machine.
It is therefore an object of this invention to improve the sealing characteristics of the resinous material with respect to the stator core.
In order to achieve above object, this invention provides a rotating electric machine comprising: a rotor; a stator including a stator core having teeth, a coil being wound around each of the teeth, a slot formed between adjacent teeth, and an end plate being disposed on the end of the stator core and made from a material which is different from the magnetic material constituting the stator core; the end plate being integrally joined with the stator core by winding the coil through the outer side of the end plate; a case for housing the rotor and the stator; and a cylindrical member which projects along the inner peripheral surface of the stator from the end plate; the cylindrical member being formed by a resinous material to be integrated with a section of the end plate.
In the rotating electric machine, a cooling passage is formed in the slot by a closing plate for closing the slot opening and a ring-shaped space for introducing a cooling medium is defined by the outer peripheral side of the cylindrical member, an end face of the stator, and the case; the ring-shaped space being connected to the cooling passage.
The details as well as other features and advantages of this invention are set forth in the remainder of the specification and are shown in the accompanying drawings.